
What It Is: The microbiome refers to the communities of microorganisms that live on and within the body. These microbial ecosystems play an active role in shaping physiology.
Why It Matters: Health is not determined by human cells alone. Microbial communities influence immunity, metabolism, and tissue stability – making them essential to understanding both health and disease.
Key Concepts

Ecological balance
vs. dysbiosis
Health depends on stable microbial ecosystems, while imbalance can disrupt function.

Host-microbe
Interactions
Human biology is shaped through continuous exchange with microbial communities.

Microbial signaling
and metabolism
Microbes influence host physiology through biochemical signals and metabolic activity.
